Improved Liquid Chromatographic Analysis of Cyclosporine in Whole Blood with Solid Phase (Bond-Elut^TM) Extraction

Abstract

We describe a simple, precise, accurate, and specific isocratic liquid chromatographic procedure for determining cyclosporine in whole blood. The cyclosporine is extracted from 1 ml of hemolyzed blood with 200 μg of cyclosporin D added per liter as internal standard, by elution from a Bond-Elut^TM C18 extraction column with 300 μl of ethanol. A 100 μl aliquot of the eluate, injected onto an octadecyl reversed phase cartridge column, is eluted with a mixture of acetonitrile and water at a flow rate of 1.0 ml/min and at 70°C. Detection is at 210 nm. The chromatography is complete in < 10 min. The minimum detection limit is 10μg/l.

Analytical recovery of cyclosporine added to whole blood pool ranged from 95 to 113% for concentration upto 2000 μg/l. Between run CV's ranged from 6.2 to 6.3%. None of the numerous drugs and steroids tested interfered with the analysis.